Kelun-Biotech first to bag TROP2 approval in lung cancer

Sichuan Kelun-Biotech Biopharma has become the first drugmaker to usher a TROP2-targeted antibody-drug conjugate to regulatory approval in lung cancer, getting a green light in China for sacituzumab tirumotecan (sac-TMT).

The MSD-partnered ADC has been approved by China's National Medical Products Administration (NMPA) as a treatment for EGFR-mutated, locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) in patients whose disease has progressed despite earlier treatment with tyrosine kinase inhibitors (TKIs) and platinum-based chemotherapy.

The milestone means that Kelun-Biotech has beaten some prominent rivals in the TROP2 ADC category - notably, AstraZeneca and Daiichi Sankyo, which filed for approval of their Datroway (datopotamab deruxtecan) candidate as a treatment for NSCLC in the US and Europe last year, but subsequently withdrew their applications after pushback from regulators. Datroway has since been approved in Japan and the US for HR-positive, HER2-negative breast cancer.

NSCLC is the second licensed indication for sac-TMT, which was approved for the treatment of triple-negative breast cancer (TNBC) in China last year. That made it the second TROP2 ADC to reach the market after Gilead Sciences' Trodelvy (sacituzumab govitecan), which is sold as a TNBC and HR+/HER2- breast cancer therapy, but missed the mark in a pivotal NSCLC trial.

The NMPA approval is based on the results of the OptiTROP-Lung03 trial, which compared sac-TMT monotherapy to chemotherapy with docetaxel and achieved a statistically significant improvement in objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).

Kelun-Biotech said the data makes sac-TMT the first ADC to show an improvement in survival in this type of lung cancer. The approval is also a boost for MSD, known as Merck & Co in the US and Canada, which licensed rights to sac-TMT in all markets outside China, Hong Kong, Macau, and Taiwan in 2022 and is now partnering with the Chinese biotech on several different ADCs.

The two partners are running no less than 10 pivotal studies in NSCLC – internationally and in China, the world's second-largest pharma market – which span later lines of treatment, as well as early post-surgery (adjuvant) treatment of early-stage disease. The studies are looking at both monotherapy and combination regimens.

Among these is the OptiTROP-Lung07 study, carried out in China, which is looking at sac-TMT in combination with AstraZeneca's blockbuster EGFR TKI Tagrisso (osimertinib) as a first-line therapy for locally advanced or metastatic NSCLC with EGFR mutations.